The present invention relates to the roller pressing mechanism of a copying machine, more particularly, to the roller pressing mechanism that allows the fixation-use upper roller to remain in the half-pressing position against the lower roller.
In some conventional copying machines, the fixing roller is composed of an upper and a lower roller that remain in contact with each other by the application of a specific amount of pressure. However, if the copying paper becomes clogged in the fixing mechanism, the copying paper cannot be smoothly removed from the machine due to the fixing pressure. There are, however, some copying machines that are divided into upper and lower halves. In these machines, the upper half applies its own weight to the upper roller so that this roller presses against the lower only when the upper half is closed. In such machines, it is easy to draw out clogged paper by raising the upper half. However, as shown in FIG. 6, unless the upper roller (101) receives load W from the upper half, the upper roller remains in a position so that it can move with the upper frame (102) as the frame pivots on its shaft (103). In other words, when the upper half is raised, the upper roller (101) contacts the lower roller (104) by means of its own weight. However, insufficient contact pressure eventually causes toner to transfer to the upper roller (101) and unavoidably stains the following copies.